The invention relates generally to a device for collecting air-borne dust generated by slitting of paperboard.
In the manufacture of corrugated paperboard, a web of double face corrugated paperboard is produced. Said web is generally several times wider than the size of the sheet needed to manufacture a blank for a corrugated box. Accordingly, it is general practice to slit the web into two or more ribbons prior to the web being transversely cut to the desired length. The edges of the web may be defective. Hence, it is conventioanl to trim the edges of the web.
The slitter may be provided with three or more rotating blades on a common shaft for slitting the web into desired widths. The blades may have a serrated edge similar to sawteeth and cooperate with a rotary bristle-face anvil roll. The web is slit while being fed over the anvil roll at high speeds. A slitter of this type is disclosed in U.S. Pat. No. 3,508,460 and the disclosure therein is incorporated hereby by reference.
Maximum utilization of a slitter described in said patent has not been achieved because the blades generate an excessive amount of dust. Under some conditions, the dust clings to the paperboard and it interferes with printing of the same. Also, the dust accumulates in the vicinity of the slitter thereby creating a nuisance and a maintenance problem.
Attempts have been made to alleviate the dust problem by using suction nozzles of the type used to remove edge trim. Such nozzles are well known to those skilled in the art. The basic problem inherent in the use of such nozzles is that they must be repositioned to suit each change of position of the slitter knives. In addition, five or six such nozzles must be utilized and adjusted each time the slitter is indexed. The resetting of the nozzles must be accomplished within a few seconds since undue delay of the web of paperboard in the double facer machine, which precedes the slitter in the corrugator line, would cause the web of paperboard to be overheated.
The dust collector includes a housing having an elongated dust inlet opening. The housing includes a manifold chamber. A plurality of partitions having generally parallel straight portions is provided in the housing. Two adjacent partitions communicate at one end with the manifold chamber and at their other end with only a portion of said opening.
The partitions are preferably arranged in the housing in a manner whereby the suction effect at various portions along the length of the opening is substantially uniform.
The dust collector is preferably utilized in a slitter for slitting a web of paperboard and supported so that the opening faces the interface between a plurality of slitting blades on a common shaft and a rotary bristle-face anvil roll.
The apparatus of the present invention overcomes the disadvantages of the prior art by removing dust at the location where it is generated. The dust collector housing has a length which is substantially equal to the length at the brush roll and a substantially uniform suction is created at spaced points along the length of the opening.
Accordingly, a primary object of the invention is to provide a slitter and dust collector therefor.
Other objects will appear hereinafter.